The present invention relates to headsets and in particular to a headset designed for underwater applications.
The conventional headset utilizes a speaker in which a electric current serves to disturb an electro-magnetic field to, in turn, drive a diaphragm to move the air in front of the diaphragm and thereby generate sound waves.
It has heretofore been proposed to provide a headset which may be used for commercial, recreational or military purposes in a water environment. Such headsets have, by and large been water resistant in that they are capable of being wetted as distinct from actually operating underwater. The reason for this is that such headsets operated on the same principal as conventional headsets, modified only in that the driver was surrounded by a water tight cup which serves to seal the ear of the user. The air captured within the cup was driven in the same manner as conventional headset speakers to produce the desired sound waves heard by the listener. The obvious drawback with such devices is that their operation relies entirely upon the seal about the listener's ear and should that seal be disturbed water would flow into the cup causing the effectiveness of the speaker to be almost entirely lost.
In addition to the conventional diaphragm-type speaker discussed above, there is a type of speaker which utilizes as its driver an inertial transducer. Such speakers are mainly used in bone conduction speakers. In an inertial transducer the vibrations of a sound source are applied to a relatively small mass connected to a relatively large mass through a spring diaphragm. The movement of the small mass with respect to the large mass causes the spring diaphragm to oscillate within an electro-magnetic field thereby generating an electric output signal. When the transducer is operating as a speaker the electric signal is used to vary the electromagnetic field to thereby drive the spring diaphragm connecting the large mass to the small mass and thereby causing the small mass to vibrate with respect to the large mass to produce sound waves. The entire transducer may be kept within a housing so that sound may be transmitted by simply placing the housing against the skull or other appropriate bone of the listener. While a sufficiently packaged inertial speaker should operate as a bone conduction device in an underwater environment, a problem arises in maintaining the transducer in position particularly on an active person such as one surfing, water skiing or the like. In addition, inertial transducer generally have a rather "tinny" sound due to the fact that the spring diaphragm is basically a single frequency device.
In view of the above it is the principal object of the present invention to provide a headset capable of operating both in air and underwater.
A further object is to provide such a device which is comfortable for the user and which may readily be applied and removed.
A still further object is to provide such a device in a form that is relatively simple and inexpensive to manufacture and assemble.
Still other objects and advantages will become apparent from a review of the following description of the present invention.